The present invention relates to wrenches, and more particularly to a ratchet wrench which comprises an annular wheel mounted in one box end thereof and having teeth on the inside for grasping and turning nuts, bolts, etc., and a ratchet mechanism mounted between the annular wheel and the box end to force the annular wheel into engagement with the box end when the wrench is rotated clockwise, or to disengage the annular wheel from the box end when the wrench is rotated counter-clockwise.
Regular combination wrenches are commonly comprised of an elongated handle having two opposite ends respectively terminating in an open end and a box end. The box end has axial teeth equiangularly spaced around the inside for positively grasping and turning nuts, bolts, etc. Because the box end cannot be ratcheted, it must be released from the nuts, bolt, etc. after one turn, then attached to the nut, bolt, etc. again, and then turned forwards for another stroke. Therefore, it is not efficient to use such a wrench to turn nuts, bolts, etc.
The present invention has been accomplished to proivde a box end wrench which eliminates the aforesaid drawbacks. According to one aspect of the present invention, the box end wrench comprises an annular wheel mounted within the box end, the annular wheel having a plurality of longitudinal teeth equiangularly spaced around the inside for grasping and turning nuts, bolts, etc., and two symmetrical pairs of grooves longitudinally disposed on the outside at two opposite locations, two pairs of stop plates respectively mounted in the grooves within the box end, and four springs respectively connected between the stop plates and the grooves to force the stop plates outwards, wherein two of the stop plates are forced into engagement with the teeth of the box end when the wrench is turned in one direction, causing the annular wheel to be turned with the box end; the stop plates are forced backwards into the grooves when the wrench is turned in the reversed direction, causing the wrench to run idle. According to another aspect of the present invention, the stop plates include a first diagonal pair and a second diagonal pair alternatively forced into engagement with the teeth of the box end.